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Information about “GRAFX”
The GRAFX library consists of over 50 FORTRAN 77 callable routines,
which allow FORTRAN programs access to the PC's graphic and other
capabilities. The graphic routines find application where emphasis is
on ease of implementation and rapid presentation of numerical data.
Three levels of capability are included. The top level requires no
knowledge of the PC or computer graphics, and is suitable for
pedagogical applications such as numerical methods instruction,
quick-look analysis of computational progress, and for the professional
who is not primarily a programmer. The middle level operates in problem
space and suports display of points, lines, circles, ellipses, boxes,
etc. to allow creation of custom displays such as map projections,
multiple graphic windows, and 3D displays. The lowest level consists of
primitives implemented in assembly language which operate in display
space to directly access display memory and access to selected DOS and
BIOS functions.
Many miscellaneous routines are included in the library. These provide
bit level access, shift, and logical (AND, OR, NOT, EOR) operations
required by some applications. A standard pseudo-random number
generator, routines to get time-of-day, time in seconds, and date are
included. A vector clipping routine is included which can be used to
clip a problem space vector before drawing lines. If you really want to
get down to the bits and bytes, PEEK & POKE routines are included to
access any location in the 8086 address space.
In addition several illustrative example FORTRAN 77 programs are
included to demonstrate usage.
FILE1699.TXT
Disk No: 1699
Disk Title: GRAFX
PC-SIG Version: S1
Program Title: GRAFX - Graphic Extension Library for FORTRAN 77
Author Version: 2.1
Author Registration: None.
Special Requirements: Fortran 77 compiler and CGA.
The GRAFX library consists of over 50 FORTRAN 77 callable routines,
which allow FORTRAN programs access to the PC's graphic and other
capabilities. The graphic routines find application where emphasis is
on ease of implementation and rapid presentation of numerical data.
Three levels of capability are included. The top level requires no
knowledge of the PC or computer graphics and is suitable for
pedagogical applications such as numerical methods instruction,
quick-look analysis of computational progress, and for the
professional who is not primarily a programmer. The middle level
operates in problem space and suports display of points, lines,
circles, ellipses, boxes, etc. to allow creation of custom displays
such as map projections, multiple graphic windows, and 3D displays.
The lowest level consists of primitives implemented in assembly
language which operate in display space to directly access display
memory and access to selected DOS and BIOS functions.
Many miscellaneous routines are included in the library. These
provide bit level access, shift, and logical (AND, OR, NOT, EOR)
operations required by some applications. A standard pseudo-random
number generator, routines to get time-of-day, time in seconds, and
date are included. A vector clipping routine is included which can be
used to clip a problem space vector before drawing lines. If you
really want to get down to the bits and bytes PEEK & POKE routines
are included to access any location in the 8086 address space.
PC-SIG
1030D East Duane Avenue
Sunnyvale Ca. 94086
(408) 730-9291
(c) Copyright 1989 PC-SIG, Inc.
GO.TXT
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║ <<<< Disk #1699 GRAFX >>>> ║
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║ To start program, see documentation. ║
║ ║
║ To print documentation, type: COPY GRAFX.DOC PRN ║
╚═════════════════════════════════════════════════════════════════════════╝
GRAFX.DOC
FORTRAN GRAPHIC EXTENSION LIBRARY FOR FORTRAN 77
(C) Copyright 1988, 1989 by Jim Farrell All Rights Reserved.
The GRAFX library consists of over 50 routines, which extend ANSI standard
FORTRAN 77 to access the PC's video display graphics capabilities and SELECTED
DOS services from FORTRAN programs. These routines are used extensively in
scientific and engineering applications, including:
o CARTOGRAPHY
o ORBITAL MECHANICS
o AERODYNAMICS
o STATISTICS
o OPERATIONS RESEARCH
o SIGNAL PROCESSING
Emphasis is on ease of use and rapid presentation of numerical data. The GRAFX
library has proven to of great value in visual validation of numerical
software algorithms and tools. Hardcopy paper plots can be made on a graphics
printer by invoking the DOS GRAPHICS command, then using the SHIFT and PRINT
SCREEN keys when a copy of the screen is desired.
GRAFX is EASY to use! If you use FORTRAN, you can take advantage of your PC's
video graphics capabilities. The top level routines were designed to be easy
to use and avoid features which would add complexity. No training or
instruction is required to use GRAFX. The library and included examples
provide everything you need to start using your PC's graphic capabilities.
GRAFX's simplicity makes it ideal for research & development, engineering
prototyping, teaching of numerical applications, or as part of a numerical
laboratory.
GRAFX is compact! While the entire library is only about 30K bytes, the low
level graphic primitive routines take only about one kilobyte. Since GRAFX is
distributed in library (.LIB) format, only the required routines are
selectively linked with your application.
GRAFX is fast! Display memory is directly manipulated, rather than using the
slower DOS and BIOS calls to light pixels. Line and shape drawing algorithms
were selected to maximize graphic performance.
The GRAFX design includes tri-level access to the PC's graphic display. At the
highest level, no knowledge of PC hardware or graphic techniques is required.
At the middle level, powerful routines allow creation of custom displays. At
the bottom level, direct access to display hardware maximizes performance. The
following sections describe each level in detail.
TOP LEVEL. At the highest level, the GRAFX library presently provides several
routines for producing plots. These routines are implemented in FORTRAN and
are hardware independent. These include:
XYPLT - Produces a x-y plot of data. The data is automatically
scaled and displayed. The maximum and minimum values are
listed. X & Y are passed as real arrays. Up to three plots may
be displayed on the screen by successive calls with iv=1..3. Ip
determines the display type: ip=0, plots points; ip=1, plots
histogram like lines from y=minimum to y(i); ip=2, plots
histogram like lines from y=0 to y(i); ip=3, plots from (0,0)
to (x,y); ip=4, plots a connected line. A WARNING is issued if
the data range seems inappropriate for the selected ip. The
usage is:
CALL XYPLT(X,Y,N,IV,IP)
TPLOT - Produces plots similar to XYPLT for equally spaced
data. Only the extreme values of the x range need be provided.
TPLOT is useful for time series data. The usage is:
CALL TPLOT(XMIN,XMAX,Y,N,IV,IP)
FCNTPLT - Produces plots similar to XYPLT for a function
y=fcn(x). Only the extreme values of the x range and the number
of points required need be provided. FCNTPLT is useful for
examining the shape of special functions. The function must be
declared intrinsic or external in the calling program. The
usage is:
CALL FCNPLT(XMIN,XMAX,FCN,N,IV,IP)
EXTERNAL FCN
or
INTRINSIC FCN
MULPLT - Sets a problem space window and permits overlayed
display of multiple data sets through successive calls. The
first call sets the plot limits.
CALL MULPLT0(XMIN,YMIN,XMAX,YMAX)
The second and successive calls pass the arrays to be plotted,
the number of points and specify the line style. IP determines
the display type ip=0, plot a point; ip=1, plot a histogram
like line from y=minimum to y(i); ip=2, plot a histogram like
line from y=0 to y(i); ip=3, plot from (0,0) to (x,y); ip=4,
plot a connected line.
CALL MULPLT(X,Y,N,IP)
HIST - Computes and displays a histogram of the distribution
of x. The n occurrences of x are counted in 100 equally spaced
bins and the maximum occurrence is listed. The usage is:
CALL HIST(X,N)
A typical sequence for using these routines is:
CALL GSET ! enter graphics mode
CALL XYPLT(X,Y,N,0,4) ! draw the plot
CALL PAUSE('MESSAGE') ! review plot
CALL ASET ! return to alpha mode
As this illustrates, no knowledge of the inner workings and hidden mechanisms
of PC graphic hardware is required. One loads data into arrays X & Y, switches
to graphic mode and invokes the routine. The call to PAUSE puts the 'message'
on the bottom line of the display and waits until a key is depressed,
permitting time to review the plot(s). Returning to alpha mode clears the
screen. The example programs included on the installation diskette contains
examples of the usage of each of the top level routines.
MID-LEVEL. The middle level GRAFX functions are invoked by the high level
routines. After setting the problem space window and display space viewport,
the routines are called using problem space units. Scaling and conversion to
the display space viewport is automatic. The mid-level routines are written in
FORTRAN. Two key mid-level routines are:
CALL WINDOW(XPMIN,YPMIN,XPMAX,YPMAX) - Sets the problem space
window. Units are the extremes of the problem at hand: altitude
in feet, time in seconds, etc. The origin is at the lower left.
The default range is 0.0 to 1.0 in both x and y. Another way to
visualize these limits is: CALL WINDOW(LEFT,BOTTOM,RIGHT,TOP).
CALL VIEW((IXDMIN,IYDMIN,IXDMAX,IYDMAX) - set the display space
viewport. Units are pixels with the origin at the lower left.
The defaults are: x ordinate, 0 to 639; y ordinate, 0 to 199.
The use of WINDOW and VIEW to create multiple displays on the screen is
illustrated by the example program VEIW9 included on the distribution
diskette.
The following two mid-level routines convert from problem units to display
units and invoke low level routines to light points and draw lines.
CALL POINT(X,Y) ! DRAW A POINT
CALL LINE(X1,Y1,X2,Y2) ! DRAW A LINE
LINE is called in turn by the following geometrical shape generators which
work in problem units.
CALL CIRCLE(X,Y,R) ! DRAW A CIRCLE
CALL ARC(X,Y,R,AB,AE) ! DRAW AN ARC
CALL BOX(X1,Y1,X2,Y2) ! DRAW A BOX
CALL ELLIPSE(X,Y,A,B,ANGLE) ! DRAW AN ELLIPSE
Several auxiliary routines are included to annotate and control the display.
PAUSE, ERROR, and WARN output a message on the bottom line and wait for a
keystroke. INFO outputs an advisory message on the bottom line and continues.
The usages are:
CALL CURSOR(ROW,COLUMN) ! POSITION THE CURSOR
CALL PUTSTR(ROW,COLUMN,'TEXT') ! OUTPUT A STRING
CALL PAUSE('MESSAGE') ! WAITS FOR A KEYSTROKE
CALL ERROR('MESSAGE') ! WAITS FOR A KEYSTROKE
CALL WARN('MESSAGE') ! WAITS FOR A KEYSTROKE
CALL INFO('MESSAGE') ! DOES NOT WAIT FOR A KEYSTROKE
The middle level GRAFX routines provide the tools to create custom plots for
specific applications. Limit checking of points and clipping of lines is not
done. It is assumed that the user has defined appropriate problem space
limits. A clipping routine is provided in the library for applications
requiring clipping.
LOW LEVEL. At the lowest level GRAFX consists of subroutines implemented in
INTEL 8086/88 assembly language. These routines provide the FORTRAN/assembly
language interface, invoke DOS and BIOS services, perform vector to raster
conversion, and directly draw points and lines in the graphic display memory.
These routines use sixteen bit arguments (INTEGER*2) and IBM screen coordinate
conventions. Their use requires a fairly detailed understanding of the PC.
CALL GSET ! enter graphic mode
CALL GCLS ! clear graphic memory
CALL ASET ! enter alpha mode
CALL ACLS ! clear alpha memory
CALL PSET(X,Y) ! turn on the pixel at x,y
CALL PCLR(X,Y) ! turn off the pixel at x,y
PTST(X,Y) ! test the pixel at x,y
CALL PLINE(X1,Y1,X2,Y2) ! draw line
CALL PCURSO(ROW,COLUMN) ! position the cursor
CALL PUTCH(CH) ! put a character
CALL BEEP ! beep the speaker
CALL REPLY ! wait for a keyboard entry
CALL LCLR ! clear to end of line
MISCELLANEOUS ROUTINES. Many miscellaneous routines are included in the
library. These provide bit level access, shift, and logical (AND, OR, NOT,
EOR) operations required by some applications. A standard pseudo-random number
generator is included in the GRAFX library to support the examples. Routines
to get time-of-day, time in seconds, and date are included. A vector clipping
routine is included which can be used to clip a problem space vector before
calling LINE. If you really want to get down to the bits and bytes PEEK & POKE
routines are included to access any location in the 8086 address space.
Programmer notes provide the details on how to use each routine in the GRAFX
library, recommendations on preferred usage, and warnings on pitfalls to
avoid. GRAFX programmer notes are in the file NOTES.DOC on the distribution
diskette.
COMPATIBILITY. GRAFX uses the IBM CGA "high-resolution" 640 X 200 pixel
monochrome graphics (mode 6). CGA is the most widely available graphics mode
on the PC. While CGA graphics has several design limitations, including a non-
square pixel/aspect ratio, lack of a scalable graphic character set, and a low
vertical resolution, GRAFX compensates by generating shapes in problem space.
The (optional) use of a 8087 numeric coprocessor makes the conversion to
display space efficient (about 20X faster). Further line drawing speed is
achieved through the use of assembly language routines to perform vector to
raster conversion and directly manipulate display memory instead of using BIOS
& DOS INT services. These routines have been tested with the IBM PC/XT/AT,
clones and compatibles with and without numeric coprocessors.
GRAFX is a FORTRAN extension that can save you time and money in solving
problems and communicating results. GRAFX is ideal for academic computing
where programming the incidental means to an end (e.g. teaching numerical
methods) and for prototyping of engineering systems. Several complete examples
are included. Additional library routines are available which support
geographic displays, numerical analysis, orbital mechanics,and numerical
simulations. For further details, custom requirements, and source code
availability; contact:
Jim Farrell
Ridge Technology
1867 Park Road, N.W.
Washington, D.C. 20010
(202) 232-1441
GRAFX DISTRIBUTION POLICY
(C) Copyright 1988, 1989 by Jim Farrell All Rights Reserved.
GRAFX is the property of Jim Farrell and is distributed by RIDGE TECHNOLOGY.
Individuals are granted a limited license to use GRAFX, and to copy and
distribute it, provided that the following conditions are met:
1) No fee may be charged, except a nominal fee to cover duplication
and mailing costs.
2) The GRAFX library and documentation files may ONLY be
distributed in their original, unmodified state.
3) GRAFX may not be distributed, in whole or in part, as part of
any commercial or government product or service without the express
written permission of Jim Farrell.
If you use this program on a regular basis register your copy. By registering
your copy, you will:
o Receive a CURRENT copy of the distribution diskette
o Get one year of technical support - by phone or written
o Be notified of updates & new products
o Provide input and ideas to help shape future products
o Help to keep software prices down, by supporting a
distribution method which doesn't rely on expensive
advertising campaigns.
GRAFX is user supported software. This means that you may copy it freely and
give the copies to anyone you wish, at no cost. They, in turn, are also
requested to register their copy if they decide to use it.
The user supported software concept (often referred to as shareware) is an
attempt to provide wide distribution of software at a low cost. It reduces the
cost of offering a new product, and hence permits many independent authors and
small companies to develop and promote products to meet the many needs of PC
owners. User supported software is a new marketing channel, where products can
be introduced at low cost.
With user supported software, everyone benefits. The user benefits by having
access to quality products at low cost, and is able to "test drive" software
thoroughly before purchasing it. The author benefits by being able to enter
the commercial software arena without first needing large sources of venture
capital.
The method only works with your support. Not just for this product, but all
user supported software. If you obtain a user supported program from a friend
or colleague, and are still using it after a couple of weeks, it is obviously
worth something to you, and it should be registered.
SITE LICENSE AGREEMENTS
Commercial and government users must obtain a site license for the use of
GRAFX. Use the order form in this manual to obtain a site license. Site
licenses are granted as of when we receive your payment. Enclosed is a site
license agreement, which should be signed and sent with your payment when
ordering a government or commercial site license. A site license does not
include additional copies of the GRAFX program disk and the GRAFX manual.
Instead, you make your own copies of the disk and manual as you need them. If
you wish, you can order additional program disks from us. See the order form
included for more details.
PROGRAM SITE LICENSE AGREEMENT
Jim Farrell provides this program and licenses its use. You assume
responsibility for the selection of the program to achieve your intended
results, and for the installation, use and the results obtained from the
program. The use of GRAFX in a commercial environment or government
organization is granted under the following terms:
1. Payment of the license fee must be made to Jim Farrell. The fee
is based on the number of computers on which GRAFX will be used, as
follows:
1 to 9 computers $35 each
10 to 24 computers $25 each
25 to 49 computers $20 each
50 to 99 computers $15 each
over 99 computers $1500 one time fee
2. You may use GRAFX on the number of computers included in the
license fee. If you have paid the fee for over 99 computers, then
you may use GRAFX on any number of computers within your
organization.
3. You may make copies of the program and documentation, in their
original, unmodified form, without restriction. You may distribute
these copies without restriction.
4. If these copies are distributed outside of your organization,
you have no obligation to control the use of those copies which are
outside of your organization.
5. You may not modify the program or charge a fee for copying or
distributing the program or its documentation.
6. It is your responsibility to make the necessary copies and to
deliver them to the computers which they will be used on. If you
wish, you can order additional GRAFX distribution diskettes.
I agree to abide by the terms and conditions of this license.
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_____________________________
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Check which items you wish to purchase:
[] Non-commercial license for the use of GRAFX at $29.95.
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$50.00 or more, not counting maintenance contracts).
[] ____ additional disks at $10.00 per disk.
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_________________________________________
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Mail this completed form with payment to:
Jim Farrell
RIDGE TECHNOLOGY
1867 Park Road, N.W.
Washington, D.C. 20010
Phone: (202) 232-1441
For program disk orders outside the U.S., please add an
additional $5, and enclose an international money order payable
in U.S. currency.
For commercial site license orders, please enclose a signed copy
of the site license agreement.
NOTES.DOC
.-
GRAFX PROGRAMMER NOTES
(C) Copyright 1988, 1989 by Jim Farrell All Rights Reserved.
GRAFX is a FORTRAN extension library of over 50 routines which gives
the FORTRAN user access to the PC's graphic video display and a
selection of DOS and BIOS services. GRAFX can save you time and money
in solving problems and communicating results. Several complete
examples are included.
The following notes provide information on how to call the GRAFX
library subroutines and functions. Most usage and conventions can be
determined from studying the example programs included on the the
distribution diskette.
-----------------------------------------------------------------------
TOP LEVEL ROUTINE NOTES
-----------------------------------------------------------------------
The following routine uses the lower level routines to produce a x-y
plot display.
-----------------------------------------------------------------------
call xyplt(x,y,n,iv,ip) ! produce x-y plots
real x(*),y(*)
A quick look x-y plot routine (scatter plot). Up to three plots may be
displayed on the screen by calling with IV=1..3. If 1 > IV > 3 then a
full screen plot is displayed. IP determines the display type IP=0,
plot a point; IP=1, plot a histogram like line from y=minimum to y(i);
IP=2, plot a histogram like line from y=0 to y(i); IP=3, plot from
(0,0) to (x,y); IP=4, plot a connected line. A WARNING is issued if
the data range is inappropriate for the selected IP.
-----------------------------------------------------------------------
The following routine uses the lower level routines to display equally
spaced samples (e.g. time series) display.
-----------------------------------------------------------------------
call tplot(xmn,xmx,y,n,iv,ip) ! produce y=f(t) plots
real y(*)
A quick look y=f(t) plot routine for equally spaced data. Up to three
plots may be displayed on the screen by calling with IV=1..3; Any other
value of IV yields a full screen plot. IP determines the display type
IP=0, plot a point; IP=1, plot a histogram like line from y=minimum to
y(i); IP=2, plot a histogram like line from y=0 to y(i); IP=3, plot
from (0,0) to (x,y); IP=4, plot a connected line. A WARNING is issued
if the data range is inappropriate for the selected IP. See example
program for a demonstration of line drawing types.
-----------------------------------------------------------------------
The following routine uses the lower level routines to display
intrinsic or external functions.
-----------------------------------------------------------------------
call fcnplt(xmn,xmx,fcn,n,iv,ip) ! produce y=fcn(x)
external fcn
or
intrinsic fcn
A quick look y=fcn(x) plot routine for n points over a range of x. Up
to three plots may be displayed on the screen by calling with IV=1..3;
Any other value of IV yields a full screen plot. IP determines the
display type IP=0, plot a point; IP=1, plot a histogram like line from
y=minimum to y(i); IP=2, plot a histogram like line from y=0 to y(i);
IP=3, plot from (0,0) to (x,y); IP=4, plot a connected line. A WARNING
is issued if the data range is inappropriate for the selected IP. See
example program for a demonstration of line drawing types.
-----------------------------------------------------------------------
The following routine uses the lower level routines to produce multiple
plot display.
-----------------------------------------------------------------------
subroutine mulplt0(xmn,ymn,xmx,ymx)
...initialize limits for multiple x-y plots
A WARNING is issued if the data range is inappropriate for the selected
IP.
subroutine mulplt(x,y,n,ip) ! produce multiple x-y plots
real x(*),y(*)
A multiple x-y plot routine. IP determines the display type IP=0, plot
a point; IP=1, plot a histogram like line from y=minimum to y(i); IP=2,
plot a histogram like line from y=0 to y(i); IP=3, plot from (0,0) to
(x,y); IP=4, plot a connected line.
-----------------------------------------------------------------------
The following routine uses the lower level routines to support
histogram display.
-----------------------------------------------------------------------
call hist(x,n) ! plot histogram
real x(*)
...routine to plot a histogram of the distribution of x. The n
occurrences of x are counted in 100 equally spaced bins. The results are
then displayed graphically.
-----------------------------------------------------------------------
MID LEVEL ROUTINE NOTES
-----------------------------------------------------------------------
GRAFX uses two include files internally:
"physcon.icl" - physical constants
"grafcom.icl" - graphic common
These are included on the distribution diskette.
Physcon.icl contains the constant PI, conversions from radians to
degrees, and earth physical constants.
Grafcom.icl contains the named COMMON /GRAFCOM/ which contains the
information to map between display space and problem space.
-----------------------------------------------------------------------
Unless otherwise noted, GRAFX assumes that the default implicit FORTRAN
conventions are:
integer*4 and real*4.
-----------------------------------------------------------------------
A BLOCK DATA module GRAFINIT initializes the problem space window to
0.0 to 1.0 in both x and y. It initializes the display space view to 0
to 639 in the x direction and 0 to 199 in the y direction. Invocation
of either WINDOW or VIEW force the loading of GRAFINIT from the
library. If you choose to use the default problem and display space
parameters without invoking either WINDOW or VIEW, the BLOCK DATA
"GRAFINIT" must be declared "external" in your program to force loading
it from the library.
-----------------------------------------------------------------------
call window(xmn,ymn,xmx,ymx) ! set problem space window
Set problem space window (left, bottom, right, top) in named COMMON
/GRAFCOM/. Origin is lower left. Next call view with display space
view. The defaults are 0.0 and 1.0 for bottom, left and top, right
respectfully.
-----------------------------------------------------------------------
call view(xmn,ymn,xmx,ymx) ! set display space view
integer xmn,ymn,xmx,ymx
Set display space window view (left, bottom, right, top) in named
COMMON /GRAFCOM/. The default is 0 to 639 for x and 0 to 199 for y.
Arguments are screen coordinates (pixels). Note that the GRAFX
convention is for the origin in the lower left corner of the screen.
ymn is the lower coordinate and ymx is the upper.
-----------------------------------------------------------------------
-----------------------------------------------------------------------
The following routines are the mid-level problem space point, line, and
shape generators. To compensate for the CGA non-linearities, shapes
are generated in problem space. The (optional) use of a 8087 numeric
coprocessor makes the conversion to display space efficient (about 20X
faster than with no 8087). Further line drawing speed is achieved
through the use of assembly language routines to perform vector to
raster conversion and direct manipulation display memory instead of
using BIOS & DOS INT services. Limit checking of points and clipping of
lines is not done. It is assumed that the user has defined appropriate
problem space limits. A clipping routine is provided in the library for
applications requiring clipping.
-----------------------------------------------------------------------
call point(xp,yp) ! light a pixel in problem space
Converts problem coordinates to display coordinates and calls pset to
light the pixel.
-----------------------------------------------------------------------
call color('BLACK')
Determine the color of lines. The default is 'WHITE' or on. In CGA
hi-res mode, there are only two possibilities. 'BLACK' turns off pixels
that are lit and can be used to erase lines.
-----------------------------------------------------------------------
call line(xp1,yp1,xp2,yp2) ! draw a problem space line (P1 ->
P2)
Converts problem coordinates to display coordinates and calls pline to
draw the line.
-----------------------------------------------------------------------
call plot(x,y,ip) ! move to problem space point P
Converts the problem coordinate to a display coordinate and moves from
the current position to x,y. If ip = 2 a line is drawn. This routine is
included to provide compatibility with CALCOMP style calls. Tests have
shown no speed advantage over subroutine line.
-----------------------------------------------------------------------
call box(x1,y1,x2,y2) ! draw a problem space box
Call line to draw the box. P1 is lower left. P2 is upper right.
-----------------------------------------------------------------------
call circle(x,y,r) ! draw a problem space circle
Uses recursive trigonometric techniques to draw a 64 line segment
circle in problem space. Only four multiplies and six additions are
inside the computational loop. X and y are the center point. R is the
radius.
-----------------------------------------------------------------------
call arc(x,y,r,ab,ae) ! draw a problem space arc
Uses a technique similar to the circle routine to draw an arc.
Parameter ab is the arc begin angle and ae is arc end angle (in
radians). Angles are measured counter-clockwise from the positive x
axis. X and y are the center point. R is the radius.
-----------------------------------------------------------------------
call ellipse(x,y,a,b,theta) ! draw an ellipse in problem space
Draw a a 64 line segment ellipse centered at x,y: the semi-major axis
is aligned delta radians CCW from the positive x axis.
a - semi-major axis; b - semi-minor axis
Uses a formulation which eliminates the use of trigonometric
trancendental functions inside the loop.
-----------------------------------------------------------------------
call cursor(irow,icol) ! position the cursor
Set A/N cursor position at (row,column). In FORTRAN, a write always
starts in column one. Cursor can be used to set the row.
-----------------------------------------------------------------------
call putstr(x,y,string) ! output a string at (x,y) on screen
integer x,y
character string*(*)
-----------------------------------------------------------------------
call pause('message') ! put pause message at bottom of the screen
call error('message') ! put error message at bottom of the screen
call warn('message') ! put warning message at bottom of the screen
call info('message') ! put advisory message at bottom of the screen
---------------------------------------------------------------------
LEVEL THREE NOTES
---------------------------------------------------------------------
GRAFX level three contains FORTRAN 77 callable primitive graphics
functions in assembler for CGA HI-RES MONO mode. The routines ASET,
GSET, ACLS, GCLS are called directly from FORTRAN applications. The
routines PSET, PLINE, and PCURSO can be call directly, but are best
used by calling the companion FORTRAN subroutines POINT, LINE, and
CURSOR.
---------------------------------------------------------------------
call gset ! set graphic; mode = 6
call gcls ! clear graphic display
call aset ! set alpha; mode = 2
call acls ! clear alpha display
---------------------------------------------------------------------
integer*2 row,column
call pset(row,column) ! turn on a pixel at screen coordinate
Directly accesses the PCs display memory and uses a variety of rather
obscure techniques (e.g. synthetic multiplication) to compute the
address of the required byte access, form the needed bit mask, and turn
on the pixel as fast and efficiently as possible.
---------------------------------------------------------------------
integer*2 row,column
call pclr(row,column) ! turn off a pixel at screen coordinate
Turn off the pixel.
---------------------------------------------------------------------
integer*2 ptst,row,column,k
k=ptst(row,column) ! test a pixel at screen coordinate
Test the PCs display memory to see if a pixel is currently on. A none
zero value indicates that the pixel is on.
---------------------------------------------------------------------
integer*2 y1,x1,y2,x2 ! coordinate p1 to p2
call pline(y1,x1,y2,x2) ! draw a line from screen coordinate p1 to p2
Implements Jack Bresenham's Fast Line Algorithm, which uses only
integer addition and subtraction operations, in 8086 assembler. This
results in the fastest possible line drawing speeds. Line color is
selected by calling COLOR or PCOLOR. The default color is white or
"on".
---------------------------------------------------------------------
integer*2 color
call pcolor(color)
Sets line color 0 = black; otherwise white. This affects all level two
routines except point and can be used to erase lines and shapes.
---------------------------------------------------------------------
FORTRAN 77 callable 16 bit logical and shift functions
--------------------------------------------------------------------
logical and function k=land(i,j)
logical or function k=lor(i,j)
logical exclusive or function k=leor(i,j)
logical not function j=lnot(i)
logical right shift function j=lshr(i,nbits)
logical left shift function j=lshl(i,nbits)
Declare these functions integer*2 in calling program. I, J, K, and
NBITS must also be integer*2
integer*2 land,lor,leor,lnot,lshr,lshl
integer*2 i,j,k,nbits
---------------------------------------------------------------------
MISCELLANEOUS ROUTINE NOTES
---------------------------------------------------------------------
character ch
integer*2 ich
ich=ichar(ch)
call putch(ich) ! put a character at current cursor position
---------------------------------------------------------------------
integer*2 row,column
call pcurso(row,column) ! position the cursor at row, column
---------------------------------------------------------------------
call beep ! beep the speaker
call reply ! wait until a key is pressed
call lclr ! clear to end of current line
---------------------------------------------------------------------
integer*2 ich
call ckey(ich) ! check to see if a key has been pressed
If a key has been pressed and a character is in the buffer, return with
ich = ASCII code, otherwise ich = 0.
---------------------------------------------------------------------
call fdate(id,im,iy) ! day month year
integer id,im,iy
call fsecs(seconds) ! return time in seconds & fraction
call delay(delt) ! delay for "delt" seconds and return
call ftime(hh,mm,ss,fss) ! time in hours, minutes, seconds
integer hh,mm,ss,fss ! and hundreths of seconds
integer*2 dd,mm,yy
call adate(dd,mm,yy) ! assembly routine to get date
integer counts
call atime(counts) ! assembly routine to get time
COUNTS can be used to seed the supplied random number generator RAND to
obtain a different list of pseudo-random numbers each time the
application is used. Time of day in seconds is equal to counts/18.2.
---------------------------------------------------------------------
subroutine clip(x1,y1,x2,y2,nc)
Clip a vector to problem space. The vector is from (x1,y1) to (x2,y2).
variable "nc" returns -1 if unplottable or the number of clips
performed (0-4). CLIP is supplied for optional use by the programmer
in applications where vectors may extend beyond the problem space window.
---------------------------------------------------------------------
call peek(iaddr,ival) ! get a two byte quantity fm iaddr
integer*4 iaddr ! physical address
integer*2 ival
---------------------------------------------------------------------
call poke(iaddr, ival) ! put a two byte quantity at iaddr
integer*4 iaddr
integer*2 ival
------------------------------------------------------------
function rnd(irk) ! pseudo-random number generator
function rand(irk) ! pseudo-random number generator
Prime modulus linear congruential generator (Lehmer generator) of the
form f(z)=a*z mod m; where a ~=sqrt(m). This version uses a=7**5,
m=2**31-1. Seed with an integer variable "irk" containing 1. Meets the
minimal Lehmer standard! See Park & Miller; "Random Number Generators:
Good Ones are Hard to Find"; Communications of the ACM; V31 N10 (1988).
WARNING: The function name RND() is used by Lahey F77L FORTRAN as a
non-standard intrinsic. When using RND with F77L declare RND external
to avoid using the non-standard intrinsic RND.
external rnd
The function RAND is included to provide the exact same service without
such a conflict. If a different sequence of random numbers is desired
each time you run a program use the atime routine to obtain a seed
based on the the time of day counter.
-----------------------------------------------------------------------
Portability
-----------------------------------------------------------------------
GRAFX was designed to be portable in three dimensions: one, portable to
other FORTRAN compilers; two, portable to other operating systems; and
three, portable to other computers and graphics hardware.
GRAFX is written in US ANSI FORTRAN 77. The only non-standard feature
used is trailing comments, which will be a FORTRAN 8X standard. No
vendor specific non-standard features are used. Any FORTRAN extensions
required are implemented as primitive subroutines or functions (such as
bit manipulation) as part of the GRAFX library.
Only a minimal set of DOS/BIOS services are used. Access to these
system services is through calls to primitive assembly language
routines which isolate specific functions.
All GRAFX graphic operations are reduced to a few primitive functions,
which are common to all graphic displays.Rather than use a lot of
display hardware dependent shape generation algorithms, all shapes are
reduced to vector operations. The graphic display hardware specific
features are isolated in one small (about 1 KB object code) set of 8086
assembly language routines.
Because portability is "designed in" applications which use GRAFX can
be moved to newer PC technology, mini/mainframe, or even to a super
computer environment easily. In fact, the design of GRAFX reflects
years of experience in designing, building and maintaining applications
which must run in IBM 30XX, DEC VAX, and INTEL 8086 environments
inclusively.
---------------------------------------------------------------------
Compatibility
---------------------------------------------------------------------
The current distribution diskette contains libraries for Lahey FORTRAN
F77L V3.0 and Lahey Personal FORTRAN 77 (LP77). The libraries were
created using the Lahey library manager (LM), supplied with F77L and
LP77. You can use the Lahey Library Manager (LM) add to the GRAFX
library or add the GRAFX routines to your current libraries.
The primitives are compatible with MS DOS Version 3.10 and later and
CGA video mode 6.
Call for information on other versions and/or source code availability.
---------------------------------------------------------------------
Suggestions for additions and improvements are greatly appreciated.
Enhancements in final testing include a scalable vector (soft)
character set which can be positioned to the nearest pixel and
additional top level routines. Color support for 640 X 480 VGA mode is
under preparation. Our priorities for introduction are a direct
reflection of your requests.
Additional library routines are available which support geographic
displays, date conversions, numerical analysis, numerical simulation,
orbital mechanics, radar systems analysis, and other scientific and
engineering applications. For further details and custom requirements,
contact:
Jim Farrell
Ridge Technology
1867 Park Road, N.W.
Washington, D.C. 20010
(202) 232-1441
.+
Directory of PC-SIG Library Disk #1699
Volume in drive A has no label
Directory of A:\
ACLS COM 8 5-19-88 12:19p
CSAT FOR 2419 3-21-89 9:15a
EXAMPLE FOR 1168 1-23-89 10:15a
F77L LIB 32768 3-13-89 11:21a
FILE1699 TXT 2961 12-11-89 5:42p
GLNK BAT 56 1-17-89 11:28a
GO BAT 38 1-01-80 1:37a
GO TXT 540 12-12-89 2:13p
GRAFCOM ICL 759 2-05-89 10:02a
GRAFX DOC 19268 5-09-89 1:12p
LINES FOR 1226 3-14-89 10:24a
LP77 LIB 37376 3-13-89 11:14a
NOTES DOC 20283 3-21-89 9:12a
PHYSCON ICL 948 1-10-89 10:07a
README 3667 5-06-89 1:06p
SFIT FOR 1953 3-21-89 9:17a
SMOTH FOR 1870 3-14-89 10:16a
STAT FOR 1084 3-14-89 10:18a
VIEW9 FOR 4308 3-14-89 10:21a
WORM FOR 1519 3-14-89 10:23a
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